This report builds on a programme of work on sexuality education for young people initiated in 2008 by UNESCO. It is also informed by several other past and ongoing initiatives related to scaling up sexuality education, as well as drawing on case studies presented at the Bogota international consultation on sexuality education, convened by UNFPA in 2010. The report emphasizes the challenges for scaling-up in terms of integrating comprehensive sexuality education into the formal curricula of schools. It aims to: Provide conceptual and practical guidance on definitions and strategies of scaling-up, given the specificities of sexuality education; Illustrate good practice and pathways for successful scale-up in light of diverse contextual parameters; Provide some principles of scaling up sexuality education that are of relevance internationally.